Insulated ice compartment for bottom mount refrigerator with controlled heater

ABSTRACT

A refrigerator includes a refrigerator cabinet, a fresh food compartment disposed within the cabinet, a freezer compartment disposed within the cabinet, an ice compartment disposed within the cabinet, and an electronic control system associated with the refrigerator and adapted to monitor and control the fresh food compartment, the freezer compartment and the ice compartment. The control system provides for energy efficient control and operation through various means, including by monitoring state of an ice maker associated with the ice compartment and controlling temperature within compartments of the refrigerator based on the ice maker state. A heater is controlled by the control system to increase energy efficiency of the refrigerator.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 11/331,941, filed Jan. 13, 2006, which is a continuation-in-partapplication of U.S. application Ser. No. 11/139,237, filed May 27, 2005,entitled INSULATED ICE COMPARTMENT FOR BOTTOM MOUNT REFRIGERATOR, hereinincorporated by reference in its entirety.

This application does not claim priority, but hereby incorporates byreference in their entirety, provisional application Ser. No. 60/613,241filed Sep. 27, 2004, entitled APPARATUS AND METHOD FOR DISPENSING ICEFROM A BOTTOM MOUNT REFRIGERATOR, and U.S. application Ser. No.11/131,701, filed May 18, 2005, entitled REFRIGERATOR WITH INTERMEDIATETEMPERATURE ICEMAKING COMPARTMENT.

BACKGROUND OF THE INVENTION

Household refrigerators generally come in three structural styles: (1) aside-by-side model wherein the freezer and refrigerator compartments areside by side; (2) a top mount model wherein the freezer compartment islocated above the refrigerator compartment; and (3) a bottom mount modelwherein the freezer compartment is mounted below the refrigeratorcompartment. An icemaker is normally provided in the freezer compartmentof all three models. A door mounted ice dispenser is often provided in aside-by-side refrigerator and in a top mount refrigerator so that aperson can add ice to a glass without opening the freezer orrefrigerator door. However, a door mounted ice dispenser normally is notbeen provided in bottom mount refrigerators, since the freezer door istoo low, and there are difficulties in transporting ice from the freezercompartment to the refrigerator compartment which precludes a dispenserin the refrigerator compartment door. However, it is desirable to havean ice dispenser in the refrigerator compartment of a bottom mountrefrigerator.

Providing an icemaking compartment within the fresh food compartment ofa refrigerator presents numerous issues, both structural and functional.For example, the fresh food compartment is normally about 40° F., whilean ice compartment needs to be less than 32° F. in order to make iceeffectively and efficiently and is typically at, or about 0° F.Maintaining and controlling the temperature within the icemakingcompartment requires insulation, seals, appropriate airflow, and acontrol system. Placing the icemaking compartment within the fresh foodcompartment of the refrigerator also requires consideration ofelectrical connections of the icemaker and the supply of water to theicemaker. The method of manufacturing of such an icemaking compartmentwithin the fresh food compartment of a refrigerator also raises noveland unique considerations which are not factors for an icemakingcompartment mounted in a freezer.

U.S. Pat. No. 6,735,959 issued to Najewicz discloses a thermoelectricicemaker placed within the fresh food compartment of a bottom mountrefrigerator that may be dispensed through the fresh food door. Najewiczforms ice within the fresh food compartment using the thermoelectricicemaker even though the compartment is above a freezing temperature.Although Najewicz provides for a duct that runs from the freezercompartment to the thermoelectric icemaker, the cold air from the ductis used to remove heat from the thermoelectric icemaker. Najewicz hasmany problems that must be overcome in order to be practical includingthe removal of unfrozen water, rapid ice body formation, prolonged icestorage, etc. The present invention overcomes these problems.

BRIEF SUMMARY OF THE INVENTION

Therefore it is a primary object, feature, or advantage of the presentinvention to improve over the state of the art.

A further object, feature, or advantage of the present invention is theprovision of an improved refrigerator having an icemaking compartmentwithin the fresh food compartment.

Another object, feature, or advantage of the present invention is theprovision of a refrigerator having a separate icemaking compartmentmaintained at a temperature between 0° and 32° F.

A further object, feature, or advantage of the present invention is theprovision of a refrigerator having an insulated icemaking compartmentremote from the freezer compartment.

Still another object, feature, or advantage of the present invention isthe provision of a bottom mount refrigerator having an icemakingcompartment integrally formed in the liner of the fresh foodcompartment.

Yet another object, feature, or advantage of the present invention isthe provision of a bottom mount refrigerator having a modular icemakingcompartment mounted in the fresh food compartment.

A further object, feature, or advantage of the present invention is theprovision of a bottom mount refrigerator having an icemaking compartmentin the fresh food compartment, and having an insulated and sealed frontcover on the icemaking compartment which can be opened to provide accessinto the compartment.

Another object, feature, or advantage of the present invention is theprovision of an icemaking compartment in the fresh food compartment of abottom mount refrigerator with a single electrical connection within theicemaking compartment for the wire harness of the icemaker.

Another object, feature, or advantage of the present invention is theprovision of an icemaking compartment in the fresh food compartment of abottom mount refrigerator wherein the water fill tube for supplyingwater to the icemaker extends downwardly through a vertically disposedhole in the top wall of the refrigerator.

Still another object, feature, or advantage of the present invention isthe provision of an icemaking compartment within the fresh foodcompartment of a bottom mount refrigerator wherein the water fill tubefor the icemaker is exposed to ambient air to prevent freezing of waterwithin the fill tube.

Yet another object, feature, or advantage of the present invention isthe provision of a bottom mount refrigerator having a recessed cavity inthe fresh food compartment in which a water tank is mounted.

A further object, feature, or advantage of the present invention is theprovision of an icemaking compartment which is formed separately fromand mounted into a fresh food compartment of a bottom mountrefrigerator.

Another object, feature, or advantage of the present invention is theprovision of a method of making a bottom mount refrigerator having anintegral ice compartment formed in the liner of the fresh foodcompartment.

Still another object, feature, or advantage of the present invention isthe provision of a control system for an ice compartment within thefresh food compartment of a refrigerator for controlling icemaking anddispensing.

Still another object, feature, or advantage of the present invention isthe provision of a refrigerator having a fresh food compartment with anicemaking compartment therein, and an ice dispenser in the door of thefresh food compartment.

Another object, feature, or advantage of the present invention is theprovision of a bottom mount refrigerator having an ice dispenser in thedoor of the refrigerator, also known as the fresh food, compartment.

Another object, feature, or advantage of the present invention is theprovision of an icemaker in the refrigerator compartment of a bottommount refrigerator, with a cold air duct to provide air from the freezercompartment to the icemaker.

Still another object, feature, or advantage of the present invention isthe provision of an icemaker in the refrigerator compartment of a bottommount refrigerator having efficient and timely icemaking capacity.

It is a further object, feature, or advantage of the present inventionto provide a bottom mount refrigerator that dispenses ice and waterthrough the door.

It is a still further object, feature, or advantage of the presentinvention to provide a refrigerator that is energy efficient.

Another object, feature, or advantage of the present invention is toprovide a refrigerator that enhances safety.

Yet another object, feature, or advantage of the present invention is toprovide a refrigerator that provides convenience to users.

A further object, feature, or advantage of the present invention is toprovide a refrigerator that is aesthetically pleasing to users.

A still further object, feature, or advantage of the present inventionis to provide a refrigerator with a control system design that minimizesthe complexity and the number of components necessary.

Another object, feature, or advantage of the present invention is toprovide a refrigerator with a drive for the ice box/fresh foodcompartment damper which provides feedback.

Yet another object, feature, or advantage of the present invention is toprovide a refrigerator with compartment light cutout.

A further object, feature, or advantage of the present invention is toprovide a refrigerator which disables the icemaker and dispenser whenthe fresh food compartment door opens.

A still further object, feature, or advantage of the present inventionis to provide a refrigerator with a menu-driven interface.

Another object, feature, or advantage of the present invention is toprovide a refrigerator with a variable speed fan.

One or more of these and/or other objects, features, or advantages ofthe present invention will become from the specification and claims thatfollow.

The bottom mount refrigerator of the present invention has an icemakerwithin an insulated icemaking compartment in the fresh food orrefrigerator compartment. Cold air is supplied to the icemakingcompartment from the freezer compartment via a cold air duct. A returnair duct extends from the icemaking compartment to the freezercompartment. The icemaking compartment also includes a vent opening forventing air to the refrigerator compartment. A fan draws or forces airthrough the duct from the freezer compartment to the icemakingcompartment. The temperature in the ice making compartment is between 0°F. to 32° F., which is colder than the temperature of the refrigeratorcompartment, but not as cold as the freezer compartment. The icemakingcompartment is preferably located in an upper corner of the refrigeratorcompartment. The door of the refrigerator compartment includes an icedispenser to supply ice to a person without opening the refrigeratorcompartment door. The door may include an ice bin for storing ice fromthe icemaker.

In the improved refrigerator of the present invention, the icemakingcompartment is insulated. Preferably, the icemaking compartment isformed integrally with the liner of the fresh food compartment.Alternatively, the icemaking compartment is formed separately from andmounted in the fresh food compartment. The icemaking compartmentincludes inner and outer shells, with insulation therebetween, as wellas an insulated front cover which provides an air-tight seal with theicemaking compartment when closed, and which can be opened to provideaccess to the icemaker and ice bin within the icemaking compartment. Thewater fill tube for the icemaking compartment extends through avertically disposed hole in the top wall of the refrigerator, and isexposed to ambient air to prevent freezing of water within the tube. Therefrigerator includes a recessed cavity in the back wall in which awater tank is mounted.

In the method of manufacturing the icemaking compartment of the presentinvention, the ice compartment is preferably formed in the liner of thefresh food compartment during the molding processing using oppositelydisposed forces. A three-dimensional plug forms the icemakingcompartment from a rear side of the fresh food compartment liner. Afront wall of the icemaking compartment is then cutout, so that an icebox can be inserted through the cutout into the icemaking compartment.

A control system is provided for the refrigerator for controlling themaking and dispensing of ice in the icemaking compartment within thefresh food compartment of the bottom mount refrigerator.

In one aspect of the invention, a refrigerator includes a refrigeratorcabinet, a fresh food compartment disposed within the cabinet, a freezercompartment disposed within the cabinet, an ice compartment disposedwithin the cabinet, and an electronic control system associated with therefrigerator and adapted to monitor and control the fresh foodcompartment, the freezer compartment and the ice compartment.Preferably, the ice compartment is positioned remote from the freezercompartment. Preferably also, two side-by-side fresh food compartmentdoors provide access to the fresh food compartment. A freezercompartment door for providing access to the freezer compartment ispreferably positioned below the two side-by-side fresh food compartmentdoors. A dispenser is associated with one of the two side-by-side freshfood compartment doors, the dispenser is adapted for dispensing ice fromthe ice compartment as well as water. The control system is adapted todisable the dispenser upon opening of the fresh food compartment doorassociated with the dispenser.

According to another aspect of the present invention, the refrigeratorincludes an ice compartment temperature sensor associated with the icecompartment and electrically connected to the electronic control system,a fresh food compartment temperature sensor associated with the freshfood compartment and electrically connected to the electronic controlsystem, a freezer compartment temperature sensor associated with thefreezer compartment and electrically connected to the electronic controlsystem, and an ambient temperature sensor electrically connected to theelectronic control system. The control system is preferably adapted forperforming the step of calculating a desired performance temperature foreach of the fresh food compartment, the freezer compartment, and the icecompartment using correlations. The control system may be adapted forperforming the step of calculating a desired performance temperature foreach of the fresh food compartment, the freezer compartment, and the icecompartment using correlations and weighting at least partially based onprior testing to thereby improve temperature stability and foodpreservation.

According to another aspect of the invention, the refrigerator mayinclude a variable speed evaporator fan, and a variable speed evaporatorfan output from the control system. The control system is adapted forsetting the variable speed evaporator fan to a plurality of rates. Thecontrol system is adapted to set the variable speed evaporator fan at afirst rate when the freezer is determined to require cooling and asecond rate when the freezer is determined not to require cooling andthe fresh food compartment is determined to require cooling, the secondrate being lower than the first rate. The control system may also beadapted to set the variable speed evaporator fan at a first rate whenthe freezer is determined to require cooling and a second rate when thefreezer is determined not to require cooling and the ice compartment isdetermined to require cooling, the second rate being lower than thefirst rate.

According to another aspect of the invention, there is a direct current(DC) mullion heater electrically connected to the control system forselectively providing heat to increase overall energy efficiency of therefrigerator.

According to another aspect of the invention, there is a cavity heaterassociated with a door of the refrigerator, the cavity heaterelectrically connected to the control system for selectively providingheat to increase overall energy efficiency of the refrigerator.

According to another aspect of the invention, there is a fresh foodcompartment light associated with the fresh food compartment to turn thefresh food compartment light off after a set time period during whichthe fresh food compartment door is open.

According to another aspect of the invention, there is a freezercompartment light associated with the freezer compartment to turn thefreezer compartment light off after a set time period during which thefreezer compartment door is open.

According to another aspect of the invention, the control system isadapted to disable the ice maker and a dispenser on the fresh foodcompartment door when the fresh food compartment door opens.

According to another aspect of the invention, the control system isadapted for performing the step of calculating a desired performancetemperature for each of the fresh food compartment, the freezercompartment, and the ice compartment using correlations. The correlationis arrived at by prior testing in a plurality of environments and usageconditions.

According to another aspect of the invention there is a damper forcontrolling air flow and the electronic control system is adapted formonitoring damper state and if the damper state indicates the damper isnot properly operating, a motor output associated with the damper ispulsed to heat and thereby free the damper. The step of monitoring caninclude monitoring lengths and sequence of a switch state associatedwith the damper and determining if the sequence is outside of atolerance level and waiting for the sequence to be within the tolerancelevel before determining the damper state.

According to another aspect of the present invention a refrigerator isprovided which includes a refrigerator cabinet, at least one compartmentdisposed within the refrigerator cabinet, a cooling system within therefrigerator cabinet, and an electronic control system associated withthe refrigerator and adapted to monitor and control temperature withinthe at least one compartment, the electronic control system adapted tocycle on and off the cooling system based on a cut-in temperature and acut-out temperature associated with at least one of the at least onecompartment, the electronic control system further adapted to adjust thecut-in temperature and the cut-out temperature during operation of therefrigerator to thereby improve temperature performance and energyefficiency of the refrigerator.

According to another aspect of the present invention, a refrigerator isprovided. The refrigerator includes a refrigerator cabinet, at least twocompartments disposed within the refrigerator cabinet, each of the atleast two compartments having a temperature sensor for sensingtemperature, and an electronic control system associated with therefrigerator, operatively connected to each of the at least twotemperature sensors for monitoring temperature within the at least twocompartments, the electronic control system further adapted tosynchronize cooling of the at least two compartments to thereby provideconsistent power consumption patterns.

According to another aspect of the present invention a refrigerator isprovided. The refrigerator includes a refrigerator cabinet, acompartment disposed within the refrigerator cabinet, a temperaturesensor associated with the compartment, and an electronic control systemoperatively connected to the temperature sensor and adapted forcalculating a desired performance temperature for the compartment usingtemperature data from the temperature sensor and temperature data basedon prior testing from locations within the compartment different from aposition of the temperature sensor within the compartment to therebyimprove temperature stability and food preservation of the refrigeratorwithout use of additional temperature sensors within the compartment.The step of calculating can include using correlation and weighting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a bottom mount refrigerator according tothe present invention.

FIG. 2 is a perspective view of the bottom mount refrigerator having thedoors removed.

FIG. 3 is a view similar to FIG. 2 showing the cold air duct and returnair duct for the icemaking compartment.

FIG. 4 is a front elevation view of the bottom mount refrigerator of thepresent invention with the doors open, and illustrating the cold air andreturn air ducts.

FIG. 5 is a sectional view taken along lines 5-5 of FIG. 4.

FIG. 6 is a sectional view taken along lines 6-6 of FIG. 4.

FIG. 7 is a perspective view of the icemaker positioned within theicemaking compartment.

FIG. 8 is a perspective view of the fresh food compartment liner withthe integrally formed icemaking compartment of the present invention.

FIG. 9 is a front elevation view of the liner shown in FIG. 8 withoutthe ice box attached.

FIG. 10 is a side elevation view of the liner shown in FIG. 8.

FIG. 11 is a perspective view of the ice box which mounts to the linerin accordance with one embodiment of the present invention.

FIG. 12 is a right side elevation view of the fresh food compartmentliner showing the water tank recess formed in the rear wall.

FIG. 13 is a partial front elevation view of the fresh food compartmentliner showing the water tank recess.

FIG. 14 is a rear perspective view of the fresh food compartment linerwith the ice box installed within the outer shell of the fresh foodcompartment.

FIG. 15 is a front perspective view of the fresh food compartment withthe ice maker and pan assembly removed for clarity.

FIG. 16 is a perspective view of the liner, box and air ducts providedfor the icemaking compartment.

FIG. 17 is a front elevation view of the ice compartment with the panassembly moved for clarity.

FIG. 18 is a view showing an internal portion of the icemakingcompartment with a wire harness cavity in an open position.

FIG. 19 is a view similar to FIG. 16 showing the wire harness cavitywith a cover installed.

FIG. 20 is a perspective view from the front of the icemaker showing thebin and front cover in a closed position.

FIG. 21 is a view similar to FIG. 14 showing the bin and front cover inan open position.

FIG. 22 is a perspective view of the ice pan, auger and motor assembly.

FIG. 23 is an exploded view of the ice pan, auger and motor assembly.

FIG. 24 is a rear elevation view of the bin assembly seal for theicemaking compartment.

FIG. 25 is a sectional view taken along lines 25-25 of FIG. 24.

FIG. 26 is a front view of the water cavity formed within the rear wallof the fresh food compartment, with the water tank assembly mountedtherein.

FIG. 27 is a front view of the fresh food compartment showing the coverinstalled over the water tank cavity.

FIG. 28 is a perspective view of the water tank assembly of the presentinvention.

FIG. 29 is an exploded view of the water tank assembly of the presentinvention.

FIG. 30 is a perspective view showing the top of the refrigerator withthe water fill tube cup mounted thereon.

FIG. 31 is an enlarged view of the water fill tube cup showing thevertical hole through which the water fill tube extends.

FIG. 32 is a sectional view taking along lines 32-32 of FIG. 31.

FIG. 33 is an exploded perspective view of the air impingement system ofthe present invention.

FIG. 34 is an assembled perspective view of the air impingement systemin the ice box.

FIG. 35 is an assembled perspective view of the ice maker in the icebox.

FIG. 36 is a view showing the male mold for forming the liner of thefresh food compartment according to the preferred embodiment of thepresent invention.

FIG. 37 is a view similar to 36 showing the plug inserted for formationof the icemaking compartment.

FIG. 38 is a view of an alternative embodiment of an icemakingcompartment formed separately from the fresh food compartment liner andmounted therein.

FIG. 39 is an exploded view of the separate ice compartment of thealternative embodiment.

FIG. 40A is a block diagram of one embodiment of a control systemaccording to the present invention.

FIG. 40B is a block diagram of another embodiment of a control systemaccording to the present invention.

FIG. 41 is a flow diagram of an executive loop according to oneembodiment of the present invention.

FIG. 42 is a flow diagram of a calculate temperatures subroutineaccording to one embodiment of the present invention.

FIG. 43 illustrates one embodiment of a flow diagram for the adjustsetpoints subroutine.

FIG. 44A illustrates one embodiment of a flow diagram for the updatefreezer subroutine.

FIG. 44B illustrates one embodiment of a flow diagram for the updatefreezer cuts subroutine.

FIG. 44C illustrates relationships between the cooling flag, control,temperature, setpoint, cut-ins, cut-outs, and cycle time for the updatefreezer cuts subroutine.

FIG. 45A illustrates one embodiment of a flow diagram for the update icebox subroutine.

FIG. 45B illustrates one embodiment of a flow diagram for the update icebox cuts subroutine.

FIG. 45C illustrates relationships between the cooling flag, control,temperature, setpoint, cut-ins, cut-outs, and cycle time for the updateice box cuts subroutine.

FIG. 46A illustrates one embodiment of a flow diagram for the updatefresh food subroutine.

FIG. 46B illustrates one embodiment of a flow diagram for the updatefresh food cuts subroutine.

FIG. 46C illustrates relationships between the cooling flag, control,temperature, setpoint, cut-ins, cut-outs, and cycle time for the updatefresh food cuts subroutine.

FIG. 47 illustrates one embodiment of a flow diagram for the updatedefrost subroutine.

FIG. 48 illustrates one embodiment of a flow diagram for the checkstable cycles subroutine.

FIG. 49 illustrates one embodiment of a flow diagram for the scan icemaker subroutine.

FIG. 50 illustrates one embodiment of a flow diagram for the controlcompressor subroutine.

FIG. 51 illustrates one embodiment of a flow diagram for the controldamper subroutine.

FIG. 52 illustrates one embodiment of a flow diagram for the controldefrost heater subroutine.

FIG. 53 illustrates one embodiment of a flow diagram for the controlevaporator fan subroutine.

FIG. 54 illustrates one embodiment of a flow diagram for the control icebox fan subroutine.

FIG. 55 illustrates one embodiment of a methodology for damper recovery.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A bottom mount refrigerator is generally designated in the drawings bythe reference numeral 10. The refrigerator 10 includes a refrigerator orfresh food compartment 12 and a freezer compartment 14. Doors 16 areprovided for the refrigerator compartment or fresh food compartment 12and a door 18 is provided for the freezer compartment 14. One of thedoors 16 includes an ice dispenser 20, which may also include a waterdispenser.

Intermediate Temperature Icemaking Compartment

An icemaking compartment or intermediate compartment 22 is provided inthe refrigerator compartment 12. The icemaking compartment 22 is shownto be in one of the upper corners of the refrigerator, or fresh food,compartment 12, but other locations are also within the scope of thisinvention. The icemaking compartment 22 has a front cover 23 that isinsulated to prevent the cold air of the icemaking compartment 22 frompassing into the refrigerator compartment and opening 21 is providedthat mates with chute 19 of the ice dispenser 20. A seal may be providedbetween the opening 21 and chute 19 to prevent cold air from passingfrom the icemaking compartment to the refrigerator compartment 12. Chute19 may be adapted to engage opening 21 upon closing of door 16. Chute 19and opening 21 may be opposingly angled as to provide added sealing uponclosing of door 16. Additionally, a intermediate piece maybe be used toimprove the seal be between chute 19 and opening 21. For example, aresilient seal may be used to assist in achieving this seal.Alternatively, a spring or other elastic material or apparatus may beutilize between or about the junction of chute 19 and opening 21. Otheralternatives for sealing between chute 19 and opening 21 should beevident to one skilled in the art.

Additionally, chute 19 should have a blocking mechanism located withinor about it to assist in preventing or decreasing the flow of air orheat transfer within chute 19. For example, a flipper door that operatesby a solenoid may be placed at the opening 21 to prevent cold air fromleaving the icemaking compartment 22 and entering into the refrigeratorcompartment.

Preferably, the icemaking compartment 22 includes an icemaker 50 (asdescribed below) that forms ice in an environment that is belowfreezing.

The icemaking compartment 22 may be integrally formed adjacent therefrigerator compartment 12 during the liner forming process andinsulation filling process. In such a process the intermediatecompartment may be separated on at least one side from the fresh foodcompartment by the refrigerator liner. Alternatively, the icemakingcompartment 22 may be made or assembled remotely from the fresh foodcompartment and installed in the fresh food compartment 12. For example,this compartment 22 may be slid into the refrigerator compartment 12 onoverhead rails (not shown) or other mounting. These methods arediscussed subsequently.

The refrigerator 10 includes an evaporator 24 which cools therefrigerator compartment 12 and the freezer compartment 14. Normally,the refrigerator compartment 12 will be maintained at about 40° F. andthe freezer compartment 14 will be maintained at approximately 0° F. Theicemaking compartment is maintained at a temperature below 32° F. orless in order to form ice, but is preferably not as cold as the freezercompartment 14. Preferably this temperature is in the range of 20° F.The walls of the icemaking compartment are insulated to facilitatetemperature control among other aspects. Grates or air vents 26 areprovided in the wall 28 between the refrigerator compartment 12 and thefreezer compartment 14 to allow air circulation between thecompartments.

Air Ducts

A cold air duct 30 extends between the freezer compartment 14 and theicemaking or specialty compartment 22. More particularly, the cold airduct 30 has a lower air inlet 32 within the freezer compartment 14 andan upper outlet end 34 connected to a fan 36 mounted on the back wall ofthe icemaker 22. The fan 36 draws cold air from the freezer compartmentand forces the cold air into the icemaker 22 so as to facilitateicemaking. It is understood that the fan 36 may be located at the inletend 32 of the cold air duct 30. The fan 36 controls the air flow fromthe freezer compartment 14 to the icemaking compartment 22 and may be avariable speed fan. The fan can be actuated by conventional means. Thecold air duct 30 preferably resides within the rear wall of therefrigerator 10, as seen in FIG. 5. The arrow 35 designates the air flowthrough the cold air duct 30.

The refrigerator 10 also includes a return air duct 38 having an upperend 40 connected to the icemaker 22, and a lower end 42 terminatingadjacent one of the air grates 26. Alternatively, the lower end 42 ofthe return air duct 38 may extend into the freezer compartment 14.Preferably, the return air duct 38 resides within the rear wall of therefrigerator 10, as seen in FIG. 6.

The icemaking compartment 22 also has an air vent for discharging airinto the refrigerator compartment 14. Thus, a portion of the air fromthe icemaking compartment 22 is directed through the return air duct 38to the freezer compartment 14, as indicated by arrow 43 in FIG. 3, andanother portion of the icemaking compartment air is vented through theopening 44 into the refrigerator compartment 12, as indicated by arrows45 in FIG. 3.

As seen in FIG. 4, the ice is discharged from the icemaker 22 in anyconventional manner. Similarly, the ice dispenser 20 functions in aconventional manner.

Icemaker

As seen in FIG. 7, an icemaker 50 is positioned within the icemakingcompartment 22 with the ice storage area 54 with auger (not shown)removed for clarity. The icemaker 50 is mounted to an impingement duct52. The impingement duct receives freezer air coming from the freezercompartment through the cold air duct 30 and the fan assembly 36. Theopening 44 vents air into the refrigerator compartment 12. The augerassembly (not shown) is provided beneath the icemaker 50 along with anice storage bin with an insulated cover 23. Impingement on the icemaker, as well as other aspects of ice making, is disclosed inApplicant's concurrently filed U.S. application Ser. No. ______ entitledREFRIGERATOR WITH IMPROVED ICEMAKER and is hereby incorporated byreference.

Control System (Generally)

As described in more detail below, a control system is provided thatutilizes the icemaking compartment 22, the cold air supply duct 30, thereturn air duct 38, the variable speed icemaking fan 36, icemakingimpingement air duct 52, an icemaking compartment thermistor (notshown), an icemaking compartment electronic control damper, fresh foodair return ducts 26, and a fresh food compartment thermistor (notshown). The above components are controlled by an algorithm thatprioritizes the making of ice unless the fresh food temperature exceedsthe set point temperature. This prioritization is achieved as follows:

i. When ice is a priority, the fresh food damper is closed and the fanruns at optimum speed. In this way, supply air from the freezercompartment 14 is discharged through the impingement air duct 52,through the ice storage area 54, and through the icemaking compartmentreturn air duct 38. One of the results of this air flow, is that ice ismade at the highest rate.

ii. When the refrigerator compartment 12 is above set point, theelectronic control damper opens and the fan runs at optimum speed. Thesupply air to the icemaking compartment is routed almost entirely intothe fresh food compartment which forces the warmer air to return to theevaporator coil of the refrigerator. This achieves a rapid return to thefresh food set point after which the damper closes and the icemakingresumes.

iii. When the ice bin is full and the fresh food temperature issatisfied, the icemaking fan runs at minimum speed. Aspects of this willinclude: reduced energy consumption; reduced sound levels; and minimizedsublimation of ice.

The above control system permits precision control of both the icemakingcompartment 22 and the refrigeration compartment 12 separately, yetminimizes the complexity and the number of component parts necessary todo so.

Thermoelectric Alternative

A thermoelectric unit (not shown) may replace the impingement duct 52with some concessions. Preferably the thermoelectric unit would contourabout the icemaker as it effectively pulls heat out of the water.Alternatively, the thermoelectric unit could be the icemaker.Regardless, it should be understood that additionally, thethermoelectric unit would require a heat sink outside of the icemakingcompartment 22 to dissipate heat. A careful balance is required betweenthe voltage of the thermoelectric unit and the temperature of therefrigerator compartment 12 if the heat sink is in the refrigeratorcompartment 12. For example, the higher the voltage, the more heat willbe generated that will be required to be removed from the refrigeratorcompartment 12. A portion of the heat generated by the thermoelectricunit may be removed by venting freezer compartment air to thethermoelectric unit.

Integral Icemaking Compartment

FIGS. 8-25 and 33-35 show the preferred embodiment of the icemakingcompartment 22, wherein the compartment 22 is integrally formed with theliner 110 of the fresh food compartment 12. The integral formation ofthe ice compartment 22 takes place during the molding of the fresh foodcompartment liner 110. The liner 110 is formed in a conventional mannerfrom a flat sheet of material using male and female molds 112, 114, asseen in FIGS. 36 and 37. The sheet material is heated and then placedbetween the open molds 112, 114, which are then closed in a vacuum box.Simultaneously, a three-dimensional plug 116 is moved in a directionopposite the male mold 112 so as to deform the sheet material from therear side opposite the male mold 112. Alternatively, the plug 116 can bestationary and the liner 110 formed around the plug 116. The plug 116forms a notch 117 in an upper corner of the liner 110. The notch 117defines an outer shell 118 of the ice compartment 22. Thus, the outershell 118 is integrally formed with the liner 110 of the fresh foodcompartment 12. After the liner 110 and the outer shell 118 arecompletely formed, the plug 116 is withdrawn and the male mold 112 isseparated from the female mold 114. The liner 110 with the outer shell118 of the ice compartment 22 is then removed and cooled. The front wallof the outer shell 118 is punched or cut so as to form an opening 120. Asecond hole 121 is punched or cut in the shell 118 for the air vent 44.The liner 112 is then moved to a punch station to trim the edges of theliner 110.

The ice compartment 22 includes a box 122 which is inserted through thefront opening 120 into the outer shell 118 so as to define an innershell. The space between the outer shell 118 and the box or inner shell122 is filled with an insulating foam, such that the ice compartment 22is insulated. This insulation process may take place at the same timethat insulation is applied between the liner 110 and the outer cabinetof the refrigerator 10. The ice box 122 includes a rear hole 123 forconnection to the cold air duct 30, a second rear hole 125 forconnection to the return air duct 38, and a side hole 127 for the ventopening 44.

Modular Icemaking Compartment

As an alternative to an icemaking compartment formed integrally in theliner 110, the compartment 22 can be formed separately and then attachedto the liner. This modular compartment is shown in FIGS. 38 and 39, andincludes the liner 110A of the fresh food compartment, and the ice box122A, which preferably is insulated. All other features and componentsof the compartment 22 are the same, other than how it is made. Themodular unit can be mounted anywhere in the fresh food compartment 12.

Wire Harness

The ice compartment 22 is adapted to receive the icemaker 50, which ismounted therein using any convenient means. The ice box 122 includes arecess 124 adapted to receive the wire harness 126 for the icemaker 50.The wire harness 126 may be adapted to allow for connection to theicemaker 50 prior to complete insertion or mounting of the ice maker 50into the compartment 12. For example, the wire harness 126 may beadapted to be operatively connected to the refrigerator near the frontportion of ice box 122 to allow for sufficient travel of the ice makerupon insertion or mounting of the ice maker 50. The wire harness 126 isoperatively connected at the rearward portion of ice maker 50. In thiscase, an assembler may connect the wire harness 126 to the ice maker 50and/or the refrigerator prior to fully inserting or mounting ice maker50 into ice box 122.

A cover 128 may be provided for the wire harness recess 124 so as toenclose the wire harness 126 prior to connecting the harness 126 to theicemaker 50. The ice box 122 has a hole 129 in a side wall to mount theconnector or clip of the wire harness.

Ice Bin Assembly

The ice compartment 22 also includes an ice bin assembly 130. Theassembly 130 is removable for assembly, service, and user access to bulkice storage. The components of the bin assembly 130 are shown in FIGS.22 and 23. The bin assembly 130 includes a tray or bin 132 for receivingice from the icemaker 50. An auger 134 is mounted within the tray 132,with the first end 136 of the auger 134 being received in a motor 138which is mounted in the upstream end 140 of the tray 132. The second end142 of the auger 134 is mounted in a housing 144 on a front plate 146 ofthe bin assembly 130. A short piece of auger flighting 143 is providedon the second end 142 of the auger 134, within the housing 144. Thehousing 144 includes an outlet opening 148, with a flipper door 150 inthe housing 144 to control opening and closing of the outlet opening148. The flipper door 150 is mounted upon a shaft 152 extending throughthe tray 132. A spring 154 mounted on the shaft 152 engages the flipperdoor 150 to normally bias the door 150 to a closed position over theoutlet opening 148. The shaft 152 can be turned by a solenoid (notshown) so as to move the flipper door 150 to an open position relativeto the outlet opening 148, such that ice can be discharged from the tray132 to the dispenser 20.

Front Cover Seal

A two-piece front cover 162 is provided on the bin assembly 130. A frontcover 162 includes an inner panel 164 and an outer panel 166, as bestseen in FIG. 23. Insulation is provided between the inner and outerpanels 164, 166, such that the front cover 162 is insulated. The innerpanel 164 mounts onto the front plate 146 of the bin assembly 130. Aseal or compressible gasket 168 (FIG. 24) is provided around the outerperimeter front plate 146 so that when the bin assembly 130 is installedinto the ice box 122, an air-tight seal is provided between the binassembly 130 and the front opening 120 of the ice compartment 22. Theseal 168 helps maintain the lower temperature of the icemakingcompartment 22, as compared to the higher temperature of the fresh foodcompartment 12.

The front cover 162 includes a latch mechanism for releasably lockingthe cover 162 to the ice compartment 22. The latch mechanism includes alock bar 170 extending through a pair of collars 172 on the front plate146 of the bin assembly 130 for lateral sliding movement between alocked and unlocked position. The lock bar 170 is normally biased to thelocked position by a spring 174. A cam 176 is mounted on a peg 178 onthe front plate 146 of the bin assembly 130 and is adapted to engage aflange or finger 180 on the end of the lock bar 170. The cam 176overcomes the bias of the spring 74 when actuated by a finger button 182mounted on the outer panel 166, so as to release the front cover 162 forremoval of the bin assembly 130. Thus, the bin assembly 130 can be slidinto the ice box 122 and retained with an air-tight seal to maintain thetemperature of the ice compartment 22. A user can depress the button 182on the bin assembly 130 to release the lock bar 170 for removal of thebin assembly 130 from the ice box 122.

Air Impingement

Another component of the icemaker 50 is an air impingement assembly 190,as shown in FIGS. 33-35. The impingement assembly 190 includes amanifold 192 and a bottom plate 194 which define an air plenumtherebetween. The manifold 192 includes a plurality of holes or nozzles196. The manifold 192 is operatively connected to the cold air duct 30so the cold air from the freezer compartment 14 is directed into themanifold 192 by the fan 36, and through the impingement nozzles 196 ontothe bottom of the mold of the icemaker 50, as best seen in FIG. 34.

The nozzles 196 are shown to be round, but may also be slotted, or anyother shape. The nozzles 196 are preferably arranged in staggered rows.The diameter of the nozzles 196, the spacing between the nozzles 196,and the distance between the nozzles 196 and the ice mold are optimallydesigned to obtain the largest heat transfer coefficient for aprescribed air flow rate. For example, in a preferred embodiment, thenozzles 196 are round with a diameter of 0.2-0.25 inches, with a spacingof approximately 1.5 inches between adjacent nozzles, and a distance of0.5-1.0 inches from the surface of the icemaker 50. The alignment of thenozzles 196 with the ice mold preferably avoids direct air impingementon the first two ice cube slots near the icemaker thermostat so as toavoid hollow ice production.

The air impingement assembly 190 speeds ice production by 2-3 times soas to meet large requirements of ice. The impingement assembly 190 isalso compact so as to permit increased ice storage space in a largersized tray 132.

Bale Plate

The ice maker 50 includes a bale plate 198 which shuts off the ice maker50 when the level of ice cubes in the tray 132 reaches a pre-determinedlevel. The plate 198 is pivotally connected to the ice maker 50 by aconnector 200 at one end of the plate 198, as seen in FIG. 35. The plate198 pivots in a vertical plane. The plate 198 is stronger than aconventional wire bale arm. The vertical orientation of the plate 198prevents ice from hanging up on the plate, which happens with a wirebale arm. The plate includes a plurality of holes 202 to reduce weightand to improve air flow.

Water Valve and Tank Assembly

Prior art refrigerators with water and ice dispensers typically locatethe water system components, such as tanks, valves, filter and tubing,throughout the refrigerator cabinet and base pan areas. This arrangementis prone to service calls to repair leaks and water restrictions due tothe larger number of connections or fittings for the components. Themultiple connections and various tubing lengths also add tomanufacturing costs.

In the present invention, the water system is pre-assembled in a singlemodule that can be quickly and easily installed. The module has lesstubing runs and connections between components as compared to prior artwater systems.

The fresh food compartment 12 includes a recess or cavity 210 in therear wall adapted to receive a water valve and tank assembly 212. Thewater valve and tank assembly 212 is shown in FIGS. 28 and 29. Theassembly 212 includes a mounting bracket 214 which is secured in therecess 212 in the back wall of the fresh food compartment 12 in anyconvenient manner. A water tank 216 is mounted on the bracket 214 andincludes a water inlet line 218 and a water outlet line 220. A cover 222attaches to the rear wall of the fresh food compartment 12 so as to hidethe water tank 216 from view when the door 16 of the fresh foodcompartment 12 is opened.

The water inlet line 218 is connected to a conventional water supplyline. The water outlet line 220 is operatively connected to a filter224. Preferably, the filter 224 is pivotally mounted in the ceiling ofthe fresh food compartment 12, as disclosed in Applicant's co-pendingapplication Ser. No. 10/195,659, entitled HINGE DOWN REFRIGERATOR WATERFILTER, filed Jul. 15, 2002, which is incorporated herein by reference.

The water filter 220 has an outlet line 226 which is connected to awater solenoid valve 228 mounted on the bracket 214. The valve 228 has afirst outlet line 230 leading to the icemaker fill tube 232 and a secondoutlet line 234 leading to the water dispenser of the refrigerator 10.Line 234 has a fitting 236 which provides a quick connection with asimple ¼ turn, without threads to the water dispenser line in the door16.

In prior art refrigerators, the water tank is normally locateddownstream of the water valve and filter, so as to prevent subjectingthe water tank to inlet water supply pressures. In this invention, thetank 216 is designed to withstand inlet water supply pressures. Thelocation of the tank 216 in the recess 210 allows greater fresh foodstorage capacity. Also, the location of the tank 216 upstream from thefilter 224 and the valve 228 will reduce the service call rate. Thedownstream location of the filter 224 also removes plastic tastesassociated with the plastic tank 216, and allows chlorinated water to bestored in the tank 216, which prevents microbiological growth on theinterior of the water tank 216.

Water Fill Tube

Prior art icemaker fill tubes are normally installed in the back of afreezer and run down a sloping tube to the icemaker. As seen in FIGS.30-32, in the present invention the water fill tube 232 for the icemaker50 extends downwardly through a vertically disposed hole 236 in the topwall 238 of the refrigerator 10. The fill tube 232 is installed from thetop of the refrigerator 10 into a plastic cup 244 positioned within arecess 246 in the top wall 238. The fill tube 232 extends through theinsulation in the top wall 238 and into the icemaker 50 in the icemakingcompartment 22. The water conduit 230 extends through the foaminsulation in the top wall 238 and through an opening 248 in the cup 244for connection to a nipple 250 on the fill tube 232. The nipple 250 isangled slightly upwardly to prevent dripping. The cup 238 is open at thetop so as to expose the fill tube 232 to the ambient air, and therebyprevent freeze-up of the fill tube 232. This vertical orientation allowsthe fill tube 232 to be positioned closer to the end of the icemaker 50.

Control System Details

The control system of a preferred embodiment of a bottom mountrefrigerator with an ice compartment is now described in greater detail.It is to be understood, however, that many of the inventive features ofthe control system have utility beyond use in conjunction with a bottommount refrigerator with an ice compartment, and in fact, such featurescan be used in refrigerators of more conventional design. Thus, what isspecifically disclosed herein is not to be unduly limited to anyspecific embodiment of a refrigerator.

FIG. 40A illustrates one embodiment of a control system of the presentinvention suitable for use in a refrigerator having three refrigeratedcompartments, namely the freezer compartment, the fresh foodcompartment, and the ice making compartment. The three compartments arepreferably able to be set by the user to prescribed set temperatures.

In FIG. 40A, a control system 510 includes an intelligent control 512which functions as a main controller. The present invention contemplatesthat the control system 510 can include a plurality of networked orotherwise connected microcontrollers. The intelligent control 512 can bea microcontroller, microprocessor, or other type of intelligent control.

Inputs into the intelligent control 512 are generally shown on the leftside and outputs from the intelligent control 512 are generally shown onthe right side. Circuitry such as relays, transistor switches, and otherinterface circuitry is not shown, but would be apparent to one skilledin the art based on the requirements of the particular intelligentcontrol used and the particular devices being interfaced with theintelligent control. The intelligent control 512 is electricallyconnected to a defrost heater 514 and provides for turning the defrostheater on or off. The intelligent control 512 is also electricallyconnected to a compressor 516 and provides for turning the compressor516 on or off. The intelligent control 512 is also electricallyconnected to a damper 518 and provides for opening or closing the damper518. The intelligent control 512 is also electrically connected to anevaporator fan 520 associated with the freezer compartment and providesfor controlling the speed of the evaporator fan 520. Of course, thisincludes setting the evaporation fan 520 to a speed of zero which is thesame as turning the evaporator fan 520 off. The use of a variable speedfan control is advantageous as in the preferred embodiment, the fan isserving an increased number of compartments with more states (freezer,fresh food, ice maker) and the ice compartment is remote from thefreezer compartment.

The intelligent control 512 is electrically connected to an ice box fan522 and provides for controlling the speed of the ice box fan 522. Ofcourse, this includes setting the ice box fan 522 to a speed of zerowhich is the same as turning the ice box fan 522 off. The intelligentcontrol 512 also receives state information regarding a plurality ofinputs. For example, the intelligent control 512 has a damper stateinput 530 for monitoring the state of the damper. The intelligentcontrol 512 also has a defrost state input 532 for monitoring the stateof the defrost. The intelligent control 512 also has a freezer doorinput 534 for monitoring whether the freezer door is open or closed. Theintelligent control 512 also has a fresh food compartment door input 536for monitoring whether the fresh food compartment door is open orclosed. The intelligent control 512 also has an ice maker state input538 for monitoring the state of the ice maker. The intelligent control512 has a freezer set point input 540 for determining the temperature atwhich the freezer is set by a user. The intelligent control 512 also hasan ice maker set point input 539. The intelligent control 512 also has afresh food compartment set point input 542 for determining thetemperature at which the fresh food compartment is set by a user. Theintelligent control 512 is also electrically connected to fourtemperature sensors. Thus, the intelligent control 512 has an ice makertemperature input 544, a freezer compartment temperature input 546, afresh food compartment input 548, and an ambient temperature input 550.The use of four separate temperature inputs is used to assist inproviding improved control over refrigerator functions and increasedenergy efficiency. It is observed that the use of four temperaturesensors allows the ice maker temperature, freezer compartmenttemperature, fresh food compartment temperature, and ambient temperatureto all be independently monitored. Thus, for example, temperature of theice box which is located remotely from the freezer can be independentlymonitored.

The intelligent control 510 is also electrically connected to a displaycontrol 528, such as through a network interface. The display control528 is also electrically connected to a mullion heater 524 to turn themullion heater 524 on and off. Usually a refrigerator has a low wattageheater to supply heat to where freezing temperatures are not desired.Typically these heaters are 120 volt AC resistive wires. Due to the factthat these heaters are merely low wattage heaters, conventionally suchheaters remain always on. The present invention uses a DC mullion heaterand is adapted to control the DC mullion heater to improve overallenergy efficiency of the refrigerator and increase safety.

The display control 528 is also electrically connected to a cavityheater 526 for turning the cavity heater 526 on and off. The displaycontrol 528 is preferably located within the door and is also associatedwith water and ice dispensement. Usually a refrigerator with a dispenserwith a display on the door will also have an associated heater on thedoor in order to keep moisture away from the electronics of thedispenser. Conventionally, this heater is continuously on.

It is to be observed that the control system 510 has a number of inputsand outputs that are not of conventional design that are used in thecontrol of the refrigerator. In addition, the control system 510includes algorithms for monitoring and control of various algorithms.The algorithms used, preferably provide for increased efficiency whilestill maintaining appropriate temperatures in the ice maker, fresh foodcompartment, and freezer.

FIG. 40B illustrates another embodiment of a control system of thepresent invention. The control system seeks to maintain a balancebetween optimum ice production and the requirements of the fresh foodand freezer compartments. This is achieved via the following inputsoperatively connected to the main 1400: ambient temperature 1402;freezer compartment set point and instantaneous temperature 1404; freshfood compartment set point and instantaneous temperature 1406; icemaking compartment set point and instantaneous temperature 1408; icemaker state 1410; ice storage compartment capacity 1412; initialrefrigerator “power up” state 1414; and defrost state 1416. These inputsare used to control the following outputs: ice maker 1418; fresh fooddamper 1420; ice making compartment set point 1422; water valve 1424;ice making compartment fan 1426; evaporator fan 1428; and compressor runtime 1430.

Based on the requirements of the system, these output functions areprioritized to seek the best solution to the heat removal rate forcooling/ice production systems as described below:

-   -   1. Multiple Pre-Set Non User-Adjustable Ice Making Compartment        Set Points        -   a. Set Point for Pull Down mode. This condition is met when            the refrigerator is first turned on (new unit or if unit has            been in storage). In this mode, the temperature inside of            the ice making compartment is ignored for a pre-set length            of time thus allowing maximum heat removal from the fresh            food and subsequently results in it reaching of set point            temperature more rapidly.        -   b. Set Point for Emergency or “Melt” modes. This condition            is met when the ice making compartment warms above a            predetermined maximum and seeks to maximize the heat removal            rate.        -   c. Set Point for ice maker turned off mode. This condition            is met when the ice maker is turned off and seeks to            minimize the heat removal rate from the ice making            compartment for optimum ice storage temperature.        -   d. Set Point for ice maker turned on mode. This condition is            met when the ice maker is turned on and the ice storage bin            is full. This condition seeks to minimize the heat removal            rate when the bin is full and maximize it very quickly when            the bin requests additional ice production (see item d).        -   e. Set Point for ice maker turned on mode. This condition is            met when the ice maker is turned on and the ice storage bin            requests additional ice production. In this mode, the heat            removal rate is maximized which may or may not result in the            ice making compartment temp being significantly less than            the set point temperature.    -   2. Ice Storage Bin Full Based on Last Time of Harvest        -   a. This condition is met when the ice maker is turned on.            The control system keeps track of time beginning at the end            of the last ice maker harvest. Based on this time interval,            the control determines whether or not the ice bin still            requesting additional ice production or is full. If the bin            is full, the system changes from a maximum heat removal to a            lesser rate thus allowing more heat removal from the freezer            and fresh food compartments.    -   3. Ice Maker Harvest Mode        -   a. This condition is met when the ice maker is on and the            control system recognizes that the ice maker is beginning            the harvest mode. Based on this information, the ice making            compartment fan turns off and the fresh food damper opens.            This operation stops the heat removal process in the ice            making compartment and optimizes the ice maker harvest time.            Additionally, by opening the fresh food damper, heat is            removed from this compartment which optimizes its            temperature.    -   4. Heat Removal Capacity in the Ice Making Mode        -   a. This condition is met when the ice maker is on. In this            mode, the control recognized the need for optimum heat            removal from the ice making compartment. In this mode, the            need for optimum heat removal rate is recognized which may            or may not result in the freezer compartment temperature            being significantly less than the set point temperature.        -   b. After the ice production mode is satisfied, the freezer            heat removal rate returns to the non-ice production mode.    -   5. Multiple Speed For the Ice Making Compartment Fan Based on        Fresh Food, Freezer, and Ice Making Compartment        -   a. This condition is met when the ice maker is on or off. In            this mode, the fan can run at two different speeds based on            the requirement for ice production or ice storage:            -   i. Ice production, temp set point a: Fan maintains                optimizes speed for this requirement            -   ii. No requirement for ice, temp set point b: Fan                optimizes speed for this requirement.            -   iii. No requirement for ice, temp set point c: Fan                optimizes speed for this requirement.            -   iv. Ice making compartment “emergency mode”, temp set                point d: Fan optimizes speed for this requirement.    -   6. Ice Making Compartment Fan Used to Cool the Fresh Food        Compartment        -   a. This condition is met when the ice maker is on or off. In            this mode, the fresh food compartment is above the            temperature set point. In this mode, the fresh food damper            opens and the fan goes to optimum speed for the required            heat removal rate. After the fresh food temperature set            point is satisfied, the damper closes, and the fan returns            to the optimum speed for heat removal rate in the ice making            compartment.            -   Note that this type of system eliminates the need for                both a second fan and second damper for the fresh food                compartment. This serves to greatly simplify the design                of the associated air channels, component wiring,                electronic hardware, and software.

The ice maker state affects the fresh food and freezer via the icemaking compartment's heat removal rate requirement. There are three mainstates that the ice maker and system operate in: (1) the ice maker isturned off; (2) the ice maker is turned on and the ice storage area isrequesting ice production; and (3) the ice maker is turned on and theice storage area is not requesting ice production.

When the ice maker is turned off, the ice making compartment controlselects the “ice storage” mode where the heat removal rate is optimized.This mode increases the heat removal capacity available for the othercompartments.

The ice maker is turned on and the ice storage area is requesting iceproduction. The control system seeks to optimize the heat removal ratefor ice production. This results in a high rate of heat removal in theice making compartment and a reduced amount of heat removal capacityavailable for the other compartments. The end result is an increasedcompressor run time to cool the freezer and an increased air damper openperiod to cool the fresh food.

When the ice maker is turned on and the ice storage area is notrequesting ice production, this results in a combination of low and highheat rate removals. The requirement is based on the ice storage arearequesting ice production or not.

The ice maker state affects the damper and evaporator fan. During theharvest mode, when the ice maker begins its harvest cycle, the freshfood damper routes the supply air away from the ice maker and into thefresh food compartment. In addition, the evaporator fan continues to runwhich allows the control system to keep the compressor running. Afterthe ice maker completes the ice harvest, the ice maker state affects thedamper and evaporator fan. In particular, the fresh food damper closesand redirects the supply air for ice production and the evaporator fancontinues to run.

Another aspect of the control system of the present invention providesfor synchronization.

The methodology reduces or eliminates non-uniform temperature patternsand produces consistent power consumption patterns during non-transientusage in a chilling and/or freezing device with more than onecompartment.

This is accomplished by making the logic controlling a slave chilledcompartment a function of both the chilled compartment sensedtemperature and primary chilled compartment cooling device (compressorstate (ON/OFF)). Namely, when the compressor turns ON, the slave chilledcompartment would also be cooled unless the slave chilled compartmenttemperature was lower than the lower temperature threshold (cut out).Likewise, when the compressor turns OFF, the slave chilled compartmentwould also stop cooling unless the slave chilled compartment temperaturewas higher than the upper temperature threshold (cut in). The slavechilled compartment would eventually be synchronized with the compressorcycles, so that every compartment employing this algorithm would attemptto cool down during the time when the compressor is on.

FIGS. 41-54 provide an exemplary embodiment of the present inventionshowing how the control system sets the states and controls refrigeratorfunctions based on those states, including states associated with thefresh food compartment, freezer compartment, and ice maker compartment.FIG. 41 is a flow diagram providing an overview of one embodiment of thepresent invention. In FIG. 41, an executive loop 560 is shown. In step562 a determination is made as to whether a set time period (such as 30seconds) has elapsed. If so, then a set of steps 564 are performed toupdate state variables. These state variables are updated through acalculate temperatures subroutine 566, an adjust setpoints subroutine568, an update freezer subroutine 570, an update ice box subroutine 572,an update fresh food compartment subroutine 574, an update defrostsubroutine 576, a check stable cycles routine 580, and a scan ice makersubroutine 582. Once the state variables are updated, then there are aset of control subroutines 566 which act on the state variables. Thesecontrol routines include a control compressor subroutine 584, a controldamper subroutine 586, a control evaporator fan subroutine 588, acontrol ice box fan subroutine 590, and a control defrost heatersubroutine 592.

As shown in FIG. 41 the status of the state variables are regularlyupdated in the set of steps 564. After the state variables are updated,appropriate actions are performed to control refrigerator functions.

The calculate temperatures subroutine 566 is shown in greater detail inFIG. 42. In one embodiment, each compartment's temperature and theambient temperature are measured with thermistors to provide raw data.Regressed temperatures are calculated based in part on the rawtemperatures.

According to one embodiment of the present invention, a mathematicregression method is used to calculate the desired performancetemperatures in each compartment using a single temperature sensingdevice in each compartment resulting in a correlation. The sensingdevice is located in a way that is preferred or reasonable for productassembly requirements, but the correlation allows the control toevaluate the product performance considering the approximatedperformance temperatures in each compartment. The approximatedperformance temperatures are developed based on the criteria that wouldbe considered by a typical consumer: the average temperatures ofmultiple locations throughout a compartment. The correlation can furtherbe mathematically manipulated to represent a variety of food stuffs ofvarious mass and density. This allows the control to react in a mannerthat optimizes the food preservation function for food stuff typesstored in each designated compartment type.

The correlation is arrived at by testing product in variety ofenvironments and usage conditions monitoring the temperatures at thesensor locations and multiple other locations in each compartment andall other compartments simultaneously. Other thermal in influences suchas ambient conditions or machine compartment conditions may also beincluded. A mathematic correlation is then calculated determining thebest fit for each temperature sensor location using some or all of thesignificant contributing measurements made from the multiple locationsof interest in the correlated compartment and the temperature sensinglocations used in other compartments. Correlations from a firstcompartment may be used as contributing factors in other compartmentscompleting a system correlation.

The correlations may be mathematically weighted by considering the mostrecent value calculated or measured as only a fraction of the fullrunning weighted value for a given compartment temperature. In factmultiple weighting values may be calculated to achieve differentapproximations of temperatures associated with food stuffs due to variedmass and densities. Additional weighting values may be desirable forother functions such as displayed temperature, other correlations,special performance modes, or historical average data storage.

The present invention uses these correlations and weighting concepts inthree compartments using four specific sensor locations. Some or all ofthese temperature locations, their compartment correlations, and somecorrelations or sensor readings and weighting of the associated valuesare used to calculate the performance temperatures for each compartment.A freezer sensor is located on the back side of the evaporator cover. Arefrigerator sensor is located inside the fresh food light housingassembly on the upper fresh food liner surface. An ice box sensor islocated in the rear of the ice making compartment. An ambienttemperature sensor is located behind the dispenser user interface faceplate. These system sensors, correlations, and weights are used toimprove product performance in a variety of ambient conditions. They areused to improve temperature stability and food preservation. They arealso used to improve energy performance and product diagnostics.

In step 1300 of the method 566 of FIG. 42, temperatures are calculatedand raw temperatures are read from each of four temperature sensors—onein the fresh food compartment (FFRaw), one on the freezer (FZRaw), onefor providing an ambient temperature (AMRaw), and one associated with anicemaker (ICRaw). In step 1304, a determination is made as to whether ornot this is the first pass through the algorithm. If it is, then in step1306 value AMEffect is set to AMRaw, FZEffect is set to FZRaw, FFEffectis set to FFRaw, and ICEffect is set to ICRaw. In step 1308, the ambienttemperature is regressed to provide AMRegressed. Note that a weighting(amcalc-am-wt) and an offset (am calc-offset) are used. Step 1310determines if this is the first pass. If it is, then in step 1312,AMControl is set to AMRegressed and AMEffect is set to AMRegressed forinitialization purposes. Returning to step 1310, if it is not the firstpass, then in step 1314, AMControl is set based on the current value ofAMControl, AMRegressed, and a constant am ctl_K. Then in step 1316,AMEffect is set based on the current value of AMEffect, AMControl, and aconstant, ameff_K.

Next, in step 1318, a regressed temperature for the freezer,FZRegressed, is calculated based on weighting (fzcalc_fz_wt,fzcalc_ff_wt, fzcalc_am_wt) of a temperature associated with the freezer(FZRaw), the effective fresh food temperature (FFEffect) and theeffective ambient temperature (AMEffect). An offset (fzcalc_offset) andan adjustment (FZAdjustment) are used in calculating the regressedtemperature for the freezer.

In step 1320, a determination is made as to whether this is the firstpass. If it is, then FZControl, FZEffect, and FZDisplay temperatures areset to the regressed temperature (FZRegressed). If this is not the firstpass, then in step 1324, a freezer control temperature (FZControl) isset based on the current FZControl, FZRegressed and a constant, fzctl_K.Then in step 1326, FZEffect is calculated based on the current FZEffect,FZControl, and a constant, fzeff_K.

Temperatures associated with the fresh food compartment are calculatedin steps 1328, 1330, 1332, 1334, and 1336 in a manner similar to thoseof the freezer compartment. Similarly temperatures associated with theice maker compartment are calculated in steps 1338, 1340, 1342, and1348. Display temperatures are calculated in step 1348 and the algorithmand in step 1350.

FIG. 43 illustrates a flow diagram for the adjust setpoints subroutine568. The user selects set points for the fresh food compartment(FFSetpoint) and the freezer compartment (FZSetpoint). Based on the usersettings, or other settings if a food saver feature is active(ff_saver_setpoint, fz_saver_setpoint), an ice maker set point(ICSetpoint) is set. Under default conditions (DEFAULT) the ice makerset point (ICSetpoint) is the same as the freezer set point(FZSetpoint). If the ice maker's bin is full (BIN_FULL), then the icemaker's set point (ICSetpoint) is set at a lower temperature to maintainthe ice and prevent melting. If the ice maker is turned off, then theice maker's set point is set at a higher temperature (ICE_EFF) therebyproviding an efficiency mode to thereby conserve energy. For example, itis generally expected that the ice maker's set point for storage(ICE_STORE) is less than the ice maker's temperature when the power isoff such as in an energy efficient mode of operation (ICE_EFF), which isless than the temperature required to melt ice. For example, the icestorage temperature (ICE_STORE) may be around 15 degrees Fahrenheitwhile the ice maker's efficiency temperature (ICE_EFF) is 25 degrees.Ice might begin to melt at a temperature of 28 degrees Fahrenheit.

Thus, in step 602 a determination is made as to whether the food saverfunction is active. If it is, then in step 604, the set point for thefresh food compartment (FFSetpoint) is set accordingly toff_saver_setpoint. Also, the set point for the freezer compartment(FZSetpoint) is set accordingly to fz_saver_setpoint and then thesubroutine proceeds to select the ice maker state in step 608. Returningto step 602, if the food saver function is not active, then in step 606,the fresh food set point (FFSetpoint) is set to a user selectedtemperature setting and the freezer set point (FZSetpoint) is set to auser selected temperature setting.

In step 608, the ice maker state is selected. If the ice maker state isturned off (PWR_OFF) to conserve energy, then the ice maker's set point(ICSetpoint) is set to an energy efficient temperature less than themelting point (ICE_EFF) in step 610. If the ice maker state indicatesthat the ice bin is full (BIN_FULL) then the ice maker's set point(ICSetpoint) is set to an ice storage temperature (ICE_STORE) in step612. If the ice maker state is the default state (DEFAULT) then the icemaker's set point (ICSetpoint) is set to the freezer set point(FZSetpoint).

FIG. 44A is a flow diagram illustrating one embodiment of the updatefreezer subroutine 570. The update freezer subroutine assists inincreasing the energy efficiency of the appliance because instead ofmerely turning on the freezer when temperature reaches a particularsetpoint, the update freezer subroutine also considers the states of thefresh food compartment and ice maker and how ultimately temperature willbe affected over time. The update freezer routing is used to set statesassociated with the freezer, fresh food compartment and ice maker. Instep 622 the fz_adj_cuts state is determined. If true then in step 630,the threshold is set to the freezer set point (FZSetpoint). If in step622, the fz_adj_cuts state is not true, then in step 628, the freezercut-in temperature (FZCutIn) is set to fz_cutin and the freezer cut-outtemperature is set to fz_cutout. Then in step 630, the threshold is setto the freezer set point (FZSetpoint).

In step 632 a determination is made as to whether the refrigerator state(FridgeState) is set to a sub-cool state (SUBCOOL). If it is, then instep 638, the Threshold is set to the difference of the Threshold andthe subcool_depression. Then in step 640, a determination is made as towhether the freezer is in the freezer cooling (FZCooling state). If itis, then in step 642, the Threshold is set to be the difference betweenthe Threshold and the freezer cut-out temperature (FZCutOut). Then instep 652, a determination is made whether the freezer controltemperature (FZControl) is less than or equal to the thresholdtemperature (Threshold). If it is, then in step 654, the freezer coolingcondition (FZCooling) is set to be FALSE and the first cut-outtemperature, CO(1), is set to the difference of the freezer setpoint(FZSetpoint) and the freezer control temperature (FZControl). Next instep 662, a determination is made as to whether the synchronize freshfood compartment with freezer (sync_ff_with_fz) or fresh food adjustcuts (ff_adj_cuts_states are TRUE. If one of these states are true, thenin step 660, the fresh food cooling state (FFCooling) is set to beFALSE. If, however, neither of these states are true, in step 670, adetermination is made as to whether the synchronize ice maker withfreezer (sync_ic_with_fz) or ice maker adjust cuts (ic_adj_cuts) statesare true. If one of these states is true, then in step 668, the icemaker cooling state (ICCooling) is set to FALSE.

Returning to step 650, if the freezer cooling state (FZCooling) is notset, then in step 646, the threshold (Threshold) is set to be the sum ofthe threshold (Threshold) and the freezer cut-in temperature (FZCutin).Then in step 648, a determination is made as to whether the threshold(Threshold) is greater than the sum of freezer's maximum set point(fz_max_setpoint) and the maximum freezer change (MAX_FZ_DELTA) dividedby two. If it is, then in step 650, the threshold (Threshold) is set tobe the sum of the freezer's maximum set point (fz_max_setpoint) and themaximum freezer change (MAX_FZ_DELTA) divided by two. Then in step 654 adetermination is made as to whether the freezer control temperature(FZControl) is greater than or equal to the threshold (Threshold). If itis, then in step 656 the freezer cooling state (FZCooling) is set to beTRUE. Then in step 658, the Update Freezer Cuts subroutine is executed.Next in step 664, a determination is made as to whether the synchronizefresh food compartment with the freezer compartment state (sync_ffwith_fz) or the fresh food adjust cuts state (ff_adj_cuts) state istrue. If it is, then in step 666 the fresh food cooling state(FFCooling) is set to be true. Then in step 672, a determination is madeas to whether the synchronize ice maker with freezer state(sync_ic_with_fz) or the ice maker adjust cuts (ic_adj_cuts) states aretrue. If they are, then in step 674, the ice maker cooling state(ICCooling) is set to be true.

FIG. 44B provides an illustration of one algorithm for an update freezercuts subroutine. Generally, the present invention provides for adjustingcuts through an algorithm which improves energy efficiency of acompartment(s) cooling system and improves temperature control ofchilled compartment(s) to a desired average temperature (set-point).

This is accomplished by:

(1) Adjusting the temperature thresholds of an on/off cooling system toproduce a repeating cyclic pattern of control at a desired frequency.Namely, when a cooling system has operated in a stable pattern for alength of time as to be thought of as non-transient operation thealgorithm will widen or compress the delta between the thresholdsperiodically to target a pre-determined frequency of on/off for thecooling system. The system is protected from affecting the thresholdsadversely by limiting the change to between max and min deltas specifiedby the algorithm.

(2) Adjusting the temperature thresholds of an on/off cooling system toproduce a repeating cyclic pattern of control about a desired averagetemperature (set-point). Namely when a cooling system has operated in astable pattern for a length of time as to be thought of as non-transientoperation, the algorithm will shift both the upper and lower thresholdsas to target the calculated average of the last stored cycle and theset-point to be equal. The system is protected from affecting thethresholds adversely by limiting the magnitude of the change for eachadjustment made.

FIG. 44B is a flow diagram illustrating one embodiment of the updatefreezer cuts subroutine 658. In step 680, the cut-in temperatures areupdated by setting the second cut-in temperature, CI(2), to be equal tothe first cut-in temperature, CI(1). The first cut-in temperature,CI(1), is then set to be equal to the difference of the freezer controltemperature (FZControl) and the freezer setpoint (FZSetpoint). Also thestable cycles variable (StableCylces) is incremented. Next in step 682,the cycle times are updated by setting the second cycle time, CT(2), tobe equal to the first cycle time, CT(1). The first cycle time, CT(1), isthen set to the current cycle time. The average cycle time (CTavg) isthen computed as the average of the first cycle time, CT(1), and thesecond cycle time, CT(2). The CT0 is set to be target cycle minutes(target_cycle_minutes).

Next in step 686, a determination is made as to whether the freezeradjust cuts state (fz_adj_cuts) is true. If it is, then in step 688, adetermination is made as to whether there are more than three stablecycles (StableCycles). If there are, then in step 690, the desired deltais calculated from the deltas and the cut-out temperatures as shown. Thebounds of the calculated desired delta are then checked in steps692-698. In step 692, a determination is made as to whether Δ(0) is lessthan the minimum freezer delta (MIN_FZ_DELTA). If it is, then in step694, Δ(0) is set to be the minimum freezer delta (MIN_FZ_DELTA). If itis not, then in step 696, a determination is made as to whether Δ(0) isgreater than the maximum freezer delta (MAX_FZ_DELTA). If it is, then instep 698, Δ(0) is set to be the maximum freezer delta (MAX_FZ_DELTA). Instep 704, the desired freezer cut-out temperature (FZCutOut) and thedesired freezer cut-in temperature (FZCutIn) are set.

Then in step 684, the deltas are updated accordingly. In particular,Δ(2) is set to Δ(1). Also, Δ(1) is set to be the sum of the average ofCI(1) and CI(2) and CO(1). Also, Δavg is set to be the average of Δ(1)and Δ(2).

FIG. 44C shows the relationship between the cooling state or flag 712,and the control temperature 708 over time. Note that at point 716,CI(1), the cooling state of flag 712 cuts in, at point 714, CI(2), thecooling state or flag also cuts in, at point 718, CO(1), the coolingstate or flag cuts out. For cycle CT(1) 722 there is an associatedaverage control temperature (Tavg) and for cycle CT(2) 720 there is anassociated average control temperature (Tavg).

FIG. 45A illustrate one embodiment of the update ice box subroutine 572.In FIG. 45A, a determination is made in step 730 as to whether theicemaker adjust cuts state (ic_adj_cuts) is true. If not, then in step734, the ice maker cut in time (ICCutIn) and the ice maker cut out(ICCutOut) times are set. Then in step 738, the threshold (Threshold) isset to the ice maker set point (ICSetpoint). Next, in step 740, adetermination is made as to whether the ice maker cooling state(ICCooling) is set. If not, then in step 746, a determination is made asto whether the freezer cooling state (FZCooling) is set. If not, then instep 743, a determination is made as to whether the synchronize icemaker with freezer state (sync_ic_with_fz) is set. If it is, then instep 744, the threshold (Threshold) is set to the sum of the Thresholdand the ice maker cut-in adjustment value (IC_CI_ADJ). In step 748, thethreshold (Threshold) is set to be the sum of the threshold (Threshold)and the ice maker cut in (ICCutIn). Next in step 752, the upper boundfor the threshold is tested and if the bound is exceeded, in step 756,the threshold is set to be the upper bound. Next in step 754, adetermination is made as to whether the ice maker control (ICControl) isgreater or equal to the threshold. If it is, then in step 762, the icemaker cooling state is set to true.

Returning to step 740, if the ice maker cooling state is true, then instep 750, the threshold is set to the difference of the threshold andthe ice maker cutout. Then in step 758, the ice maker cooling state isset to be false.

In step 764 a determination is made as to whether the ice maker waspreviously in a cooling state. If not, then in step 766 a determinationis made as to whether the ice maker cooling state is true. If not, thenthe first cut-out time, CO(1) is set to be the difference between theice maker setpoint (ICSetpoint) and the ice maker control (ICControl).If it is, then in step 772, an update ice box cuts subroutine isexecuted. In step 770, the previous ice maker cooling stat (ICCoolPrev)is set to cooling (ICCooling).

FIG. 45B illustrates the ice box cuts subroutine 772. In step 780, thecut-ins are updated. In step 782 the deltas are updated. In step 784, adetermination is made as to whether the ice_adj_cuts state is true. Ifit is, then in step 786 a determination is made as to whether there havebeen at least three stable cycles. If so, in steps 788, 790, 792, and794, the boundaries of Δ0 are tested. In step 796 the desired cuts arecalculated.

FIG. 45C shows the relationship between the cooling state or flag 800,and the control temperature 814 over time. Note that at point 812,CI(1), the cooling state of flag 800 cuts in, at point 816, CI(2), thecooling state or flag also cuts in, at point 822, CO(1), the coolingstate or flag cuts out. For cycle CT(1) 818 there is an associatedaverage control temperature (Tavg) and for cycle CT(2) 820 there is anassociated average control temperature (Tavg).

FIG. 46A illustrates one embodiment of a flow diagram for the updatefresh food subroutine 574. In FIG. 46A, a determination is made as towhether the ice maker state (IMState) is melting. If it is, then in step858, the fresh food compartment cooling state is set to false. If it isnot, then in step 856 a determination is made as to whether the freezercooling state (FZCooling) is true. If it is not then in step 858 thefresh food compartment cooling (FFCooling) state is set to false. If thefreezer cooling (FZCooling) state is true, then in step 860, adetermination is made as to whether the ff_adj_cuts state is true. If itis not, then in step 866 values for the fresh food cut-in and cut-outvalues are set accordingly. In step 868, the threshold (Threshold) isset to the fresh food compartment setpoint. In step 870, a determinationis made as to whether the fresh food cooling (FFCooling) state is true.If not in the fresh food cooling (FFCooling) state, then in step 872, adetermination is made as to whether the freezer cooling state is true.If it is then, the threshold is set in step 878. If it is not, then instep 874 a decision is made as to whether the threshold needs to beadjusted to compensate for the synchronization state. If it does notthen, in steps 876 and 878 the threshold is adjusted accordingly. Thenin step 880 a determination is made as to whether the fresh foodcompartment temperature is greater than or equal to the threshold. If itis, then in step 882, the fresh food cooling state (FFCooling) is set tobe true.

Returning to step 870, if the fresh food compartment cooling (FFCooling)state is true, then the threshold is modified in step 884. In step 886 adetermination is made as to whether the threshold is less than thedifference of the fresh food compartment's minimum setpoint and half ofthe maximum fresh food compartment change. If it is, then in step 890,the threshold is set to the difference of the fresh food compartment'sminimum setpoint and half of the maximum fresh food compartment change.Then in step 888 a determination is made as to whether the fresh foodcompartment control temperature is less than or equal to a threshold. Ifit is then the fresh food cooling state (FFCooling) is set to be false.In step 894, the fresh food cooling's previous state (FFCoolPrev) iscompared to the present fresh good cooling (FFCooling). If they are notequal, then in step 896, a determination is made as to whether the freshfood cooling (FFCooling) state is true. If it is then, an Update FreshFood Cuts subroutine 898 is run to update cut-in and cut-outtemperatures. If it is not then the cutout temperature, CO(1), is set tobe the difference between the fresh food setpoint (FFSetpoint) and thefresh food control setting (FFControl). Then in step 900 the previousfresh food cooling state (FFCoolPrev) is updated to the current freshfood cooling state.

FIG. 46B illustrates one embodiment of a flow diagram for the updatefresh food cuts subroutine 898. In step 910 the cut-in temperatures areupdated. In step 912, the deltas are updated. In step 914, adetermination is made as to whether the fresh food compartment cut-inand cut-out temperatures need adjustment. If they do, in step 916 adetermination is made as to whether there has been more than threeconsecutive stable cycles. If there has, then in steps 918, 920, 922,and 924, the delta is recalculated. In step 930 the cut-in and cut-outtemperatures for the fresh food compartment are adjusted accordingly.

FIG. 46C illustrates relationships between the cooling flag, control,temperature, setpoint, cut-ins, cut-outs, and cycle time for the updatefresh food cuts subroutine. FIG. 46C shows the relationship between thecooling state or flag 932, and the control temperature 934 over time.Note that at point 936, CI(1), the cooling state of flag 932 cuts in, atpoint 940, CI(2), the cooling state or flag also cuts in, at point 938,CO(1), the cooling state or flag cuts out. For cycle CT(1) 942 there isan associated average control temperature (Tavg) and for cycle CT(2) 944there is an associated average control temperature (Tavg).

FIG. 47 illustrates one embodiment of a flow diagram for the updatedefrost subroutine 576. In step 950 a determination is made as towhether to force a defrost. If a defrost is not forced, then in step 952the refrigerator state is selected. If a defrost is forced, then in step984 the defrost hold period is set, the refrigerator state is set todefrost and a flag for forcing a defrost is cleared.

Returning to step 952, the refrigerator state can be COOL, SUBCOOL,WAIT, DEFROST, DRIP, or PULLDOWN. If the refrigerator state is cool,then in step 956 a determination is made as to whether defrost is due.If it is, then in step 960 the defrost timer is set and in step 965, thefreezer cooling (FZCooling) state is set to true and the refrigeratorstate is set to SUBCOOL.

Returning to step 952, if the refrigerator is in the subcool state, thenin step 966 a determination is made as to whether the defrost timer hasexpired. If it has, then in step 970, the defrost timer is set and instep 976 the refrigerator state (FridgeState) is set to WAIT. If in step966 the defrost timer has not expired, then in step 972 a determinationis made as to whether the freezer is in the cooling state. If it is not,then in step 970 the defrost timer is set and in step 976 therefrigerator state (FridgeState) is set to WAIT.

Returning to step 952, if the refrigerator state (FridgeState) is WAIT,then in step 978 a determination is made as to whether the defrost timerhas expired. If it has, then in step 980 the defrost hold period is setand the refrigerator state is set to DEFROST.

Returning to step 952, if the refrigerator state (FridgeState) isDEFROST, then in step 982, a determination is made as to whether thedefrost is complete. If it is then in step 984, the defrost timer is setfor time associated with dripping (drip_time), the refrigerator state(FridgeState) is set to DRIP and the flag associated with forcingdefrost is cleared.

Returning to step 952, if the refrigerator state (FridgeState) is DRIP,then in step 986, a determination is made as to whether the defrosttimer has expired. If it has, then in step 988, the defrost timer is setand the refrigerator state is set to PULLDOWN.

Returning to step 980, if the state is PULLDOWN, a determination is madeas to whether or not the defrost timer has expired. If it has then instep 992, the freezer cooling state (FZCooling) is set to true and therefrigerator state (FridgeState) is set to COOL.

In step 996, a determination is made as to whether the refrigerator isin a DEFROST or COOL state. If it is, then the subroutine ends. If it isnot, then in step 994 a determination is made as to whether the defrosttimer has expired. If it has then the process returns to step 952. Ifthe defrost timer has not expired then the subroutine ends.

FIG. 48 illustrates one embodiment of a flow diagram for the checkstable cycles subroutine 580. The number of stable cycles is reset instep 1088 if in step 1080 the refrigerator is in the defrost state, instep 1082 the fresh food or freezer doors are open, in step 1084 thefresh food setpoint has changed, or in step 1086 the freezer setpointhas changed.

FIG. 49 illustrates one embodiment of a flow diagram for the scan icemaker subroutine 582. This subroutine scans the ice maker to check forvarious conditions that may affect control functions and sets statesassociated with the ice maker appropriately. In step 1100 adetermination is made as to whether the ice maker is in initialpulldown. If it is not, then in step 1102 a determination is made as towhether the ice maker control is above the melting temperature of ice.If it is then in state 1104, the ice maker state is set to MELTING. Ifnot, then in step 1106 a determination is made as to whether the freshfood compartment door is open. If it is, then in step 1108 the ice makerstate is selected. If the ice maker state is MELTING, then in step 1110the ice maker state is set to the previous ice maker state. If the icemaker state is set to HTR_ON then in step 1112 a determination is madeas to whether the fresh food compartment door has been open for longerthan a set dwell time. If it has, then in step 1110 the ice maker stateis set to the previous ice maker state. If has not then in step 1114 theice maker state remains unchanged. Similarly if the ice maker state isDEFAULT in step 1108 then the ice maker state remains unchanged in step1114.

In step 1116 a determination is made as to whether the ice maker poweris on. If not, then in step 1118 the ice maker state and the ice maker'sprevious state are set accordingly to indicate that the power is off. Instep 1120 a determination is made as to whether the ice maker's heateris on. If it is no then in step 1124 the ice maker's state is set toindicate that the heater is on. In step 1122 a determination is made asto whether the icemaker has been on less than a set dwell time. If ithas, then in step 1124 the ice maker's state is set to indicate that theheater is on.

In step 1126 a determination is made has to whether the ice maker'sheater has been on less than the amount of time associated with a fullbin (such as 120 minutes). If it has then in step 1128 the ice maker'scurrent state and previous state are set to indicate that the heater isoff. If not, then in step 1130 the ice maker's current state andprevious state are set to indicate that the bin is full.

FIG. 50 illustrates one embodiment of a flow diagram for the controlcompressor subroutine 584. In step 1150 the refrigerator's state(FridgeState) is examined. If the refrigerator is in the COOL state,then in step 1152 a determination is made as to whether the freezercooling state is true. If it is not, then in step 1154 a request is madeto turn the compressor off. If it is, then a request is made in step1156 to request that the compressor be on. If the state is SUBCOOL orPULLDOWN, then in step 1158 a request is made to turn the compressor on.If the state is DEFAULT, then in step 1160 a request is made to turn thecompressor off.

FIG. 51 illustrates one embodiment of a flow diagram for the controldamper subroutine 586. In step 1170 the refrigerator state is selected.If the refrigerator state is COOL or SUBCOOL then in step 1172 the icemaker state is selected. IF the ice maker state is HTR_ON then in step1174 a determination is made as to whether the evaporator fan is on. Ifit is then in step 1174 a request is made for the damper to be open. Ifnot, then in step 1178 a request is made for the damper to be closed. Ifin step 1172 the icemaker state is MELTING< then in step 1178 a requestis made for the damper to be closed. If the ice maker is in a differentstate (DEFAULT) then in step 1180 a determination is made as to whetherthe fresh food compartment is cooling. If it is not, then in step 1178 arequest is made for the damper to be closed. If it is, then in step 1182a request is made for the damper to be open. Returning to step 1170, ifthe refrigerator is in a DEFAULT state, then in step 1184 a request ismade to close the damper.

FIG. 52 illustrates one embodiment of a flow diagram for the controldefrost heater subroutine 592. In step 1200 the refrigerator state isselected. If the refrigerator state is DEFROST or DRIP, then in step1202 the defrost heater is turned on. If the refrigerator state is adifferent or DEFAULT state then in step 1204 the defrost heater isturned off.

FIG. 53 illustrates one embodiment of a flow diagram for the controlevaporator fan subroutine 588. In step 1210, the refrigerator state(FridgeState) is selected. If the state is COOL or SUBCOOL then in step1212 a determination is made as to whether the ice maker is in themelting state (MELTING). If it is, then in step 1214, the evaporator fanis turned full-on at the rail voltage. If not, then in step 1216, adetermination is made as to whether the freezer is in a cooling(FZCooling) state. If it is, then in step 1218, the evaporator fan isturned on at less than the rail voltage. If not, then in step 1220, adetermination is made as to whether the ice compartment is cooling(ICCooling).

The evaporator fan motor speed is adjusted based upon the state of theice making compartment, the freezer compartment and the fresh foodcompartment as shown in FIG. 53. The first step is to check therefrigerator state, if the state is cool or subcool then if the icemaking compartment is above a predetermined temperature (defined asMELTING in step 1212) the fan motor is energized at the highest voltageto produce the maximum air flow. If the ice making compartment is notabove the MELTING temperature, then the state of the freezer compartmentis evaluated. If the freezer compartment requires cooling, the fan isenergized at a high speed to provide the air flow required to adequatelycool the freezer compartment, if the freezer does not require cooling,then the fresh food compartment and the ice making compartment areevaluated; if the fresh food requires cooling or if the ice makingcompartment requires cooling then the fan is energized at a lowervoltage to maintain a continuous flow of air through the evaporatorcompartment without over cooling the freezer compartment. If the airdamper is opening or closing then the fan is energized at the lowervoltage. If none of these conditions are true, the fan is turned off.

FIG. 54 illustrates one embodiment of a flow diagram for the control icebox fan subroutine 590. In step 1230, a refrigerator state (FridgeState)is determined. If the refrigerator state is COOL or SUBCOOL, then instep 1232, the ice maker state is selected. If the ice maker state isMELTING, then the ice box fan is turned full-on in step 1240 such as byapplying the rail voltages to the ice box fan. If the ice maker stateindicates that the heater is on (HTR_ON), then the ice box fan is turnedof in step 1242. If the ice maker state is in a different or DEFAULTstate, then in step 1234 a determination is made as to whether the freshfood compartment is in a cooling (FFCooling) state. If it is, then instep 1244 the ice box fan is turned at less than full voltage toconserve energy. If not, then in step 1236 a determination is made as towhether the ice compartment is in a cooling (IceCooling) state. If it isin then in step 1246, the icebox fan Is turned on at a higher voltagethan in step 1244. In step 1238, if neither the fresh good compartmentis cooling or the ice maker compartment is cooling, the ice box fan isturned off. Thus the ice box fan is controlled in an energy efficientmanner.

Another aspect of the control system relates to damper operation.Referring to FIG. 40A, the damper 518 is a switched input. As shown inFIG. 55, one methodology provides for monitoring the switched input andtiming the lengths and sequences of the switch state in step 1502. Instep 1504 a determination is made as to whether the sequence of switchopenings and closings is out of tolerance. If they are, then step 1506provides for waiting for proper timing sequences to determine damperstate. In step 1508, a determination is made as to whether or not thedamper is operating properly. If the damper is not operating properlybecause it is frozen in place, then in step 1510 the motor outputassociated with the damper is pulsed. This action uses the motor as aheater to free the damper.

The invention has been shown and described above with the preferredembodiments, and it is understood that many modifications,substitutions, and additions may be made which are within the intendedspirit and scope of the invention.

1. An improvement to a refrigerator having a refrigerator cabinet and adoor for providing access to a compartment within the refrigeratorcabinet, the improvement comprising a heater for selectively providingheat to thereby increase overall energy efficiency of the refrigerator.2. The improved refrigerator of claim 1 an electronic control systemoperatively connected to the heater to turn the heater off and on. 3.The improved refrigerator of claim 1 wherein the heater is a cavityheater located within the door.
 4. The improved refrigerator of claim 1wherein the heater is a mullion heater.
 5. The improved refrigerator ofclaim 1 wherein the compartment is a fresh food compartment disposedwithin the cabinet; and further comprising: a freezer compartmentdisposed within the cabinet; a damper for controlling air flow betweenthe freezer compartment and the fresh food compartment; and anelectronic control system adapted for monitoring damper state and if thedamper state indicates the damper is not properly operating, pulsing amotor associated with the damper to heat and thereby free the damper. 6.The improved refrigerator of claim 1 further comprising: a coolingsystem within the refrigerator cabinet; an electronic control systemassociated with the refrigerator and adapted to monitor and controltemperature within the compartment, the electronic control systemadapted to cycle on and off the cooling system based on a cut-intemperature and a cut-out temperature associated with the compartment,the electronic control system further adapted to adjust the cut-intemperature and the cut-out temperature during operation of therefrigerator to thereby improve temperature performance and energyefficiency of the refrigerator.
 7. The improved refrigerator of claim 6wherein the control system is further adapted to adjust the cut-in andcut-out temperature during operation to produce cycles where theobserved average temperature of the previous on-off cycle is more equalto the desired set-point to thereby improve temperature performance. 8.The improved refrigerator of claim 1 further comprising: a secondcompartment disposed within the refrigerator cabinet, each of thecompartments having a temperature sensor for sensing temperature; anelectronic control system associated with the refrigerator, operativelyconnected to each of the temperature sensors for monitoring temperaturewithin the compartments, the electronic control system further adaptedto synchronize cooling of the compartments to thereby provide consistentpower consumption and eliminate non-uniform temperature patterns.
 9. Theimproved refrigerator of claim 1 further comprising: a temperaturesensor associated with the compartment; an electronic control systemoperatively connected to the temperature sensor and adapted forcalculating a desired performance temperature for the compartment usingtemperature data from the temperature sensor and temperature data basedon prior testing from locations within the compartment different from aposition of the temperature sensor within the compartment to therebyimprove temperature stability and food preservation of the refrigeratorwithout use of additional temperature sensors within the compartment.10. The improved refrigerator of claim 9 wherein the step of calculatingincludes using correlation and weighting.
 11. A improved refrigerator ofclaim 1 wherein the compartment is a fresh food compartment disposedwithin the cabinet; and further comprising: a freezer compartmentdisposed within the cabinet; an ice compartment with an ice makerdisposed within the cabinet; an electronic control system associatedwith the refrigerator and adapted to monitor and control temperature inthe fresh food compartment, the freezer compartment and the icecompartment.
 12. The improved refrigerator of claim 11 wherein the icecompartment is positioned remote from the freezer compartment.
 13. Theimproved refrigerator of claim 11 further comprising: an ice compartmenttemperature sensor associated with the ice compartment and electricallyconnected to the electronic control system; a fresh food compartmenttemperature sensor associated with the fresh food compartment andelectrically connected to the electronic control system; a freezercompartment temperature sensor associated with the freezer compartmentand electrically connected to the electronic control system; and anambient temperature sensor electrically connected to the electroniccontrol system.
 14. The improved refrigerator of claim 11 wherein thecontrol system is adapted for performing the step of calculating adesired performance temperature for each of the fresh food compartment,the freezer compartment, and the ice compartment using correlation. 15.The improved refrigerator of claim 11 wherein the control system isadapted for performing the step of calculating a desired performancetemperature for each of the fresh food compartment, the freezercompartment, and the ice compartment using correlation and weighting atleast partially based on prior testing to thereby improve temperaturestability and food preservation.
 16. The improved refrigerator of claim11 further comprising a variable speed evaporator fan, and a variablespeed evaporator fan output from the control system, the control systemadapted for setting the variable speed evaporator fan to a plurality ofrates.
 17. The improved refrigerator of claim 11 further comprising: anice compartment temperature sensor associated with the ice compartmentand electrically connected to the electronic control system; a freshfood compartment temperature sensor associated with the fresh foodcompartment and electrically connected to the electronic control system;a freezer compartment temperature sensor associated with the freezercompartment and electrically connected to the electronic control system;and wherein the electronic control system being further adapted tosynchronize cooling of the ice compartment, fresh food compartment, andfreezer compartment to thereby provide consistent power consumption andeliminate non-uniform temperature patterns.
 18. The refrigerator ofclaim 11 wherein the electronic control system is adapted to monitor astate of the ice maker and control temperature of the fresh foodcompartment, temperature of the freezer compartment, and temperature ofthe ice compartment at least partially based on the state of the icemaker.
 19. A bottom mount refrigerator, comprising: a refrigeratorcabinet; a fresh food compartment disposed within the cabinet; a freezercompartment disposed within the cabinet beneath the fresh foodcompartment; an ice compartment with an ice maker disposed within thecabinet; an electronic control system associated with the refrigeratorand adapted to monitor and control the fresh food compartment, thefreezer compartment and the ice compartment; and a heater operativelyconnected to the control system which periodically activates the heaterto increase energy efficiency of the refrigerator.
 20. The refrigeratorof claim 19 further comprising: an ice compartment temperature sensorassociated with the ice compartment and electrically connected to theelectronic control system; a fresh food compartment temperature sensorassociated with the fresh food compartment and electrically connected tothe electronic control system; a freezer compartment temperature sensorassociated with the freezer compartment and electrically connected tothe electronic control system; and an ambient temperature sensorelectrically connected to the electronic control system.